Field of the Invention
The present invention relates to an object information acquiring apparatus and a laser apparatus.
Description of the Related Art
As one type of light imaging technology using light, there is photoacoustic imaging (PAI). With photoacoustic imaging, a living body as an object is irradiated with pulsed light, and acoustic waves that are generated at an object segment, such as a tumor, based on the energy absorption of the pulsed light are received with a probe. In addition, by subjecting a reception signal output from the probe to analytical processing, optical characteristic distribution in the living body can be acquired as image data.
Japanese Patent Application Laid-Open No. 2010-022812 discloses an apparatus which holds a breast from both sides with holding members, and receives acoustic waves while a probe performs two-dimensional scanning above the holding members. As a result of using a probe to perform two-dimensional scanning, characteristic information relating to a plurality of positions in the object can be acquired.
Moreover, the technique of calculating the abundance ratio of substances with different optical absorption spectrums by using signals of acoustic waves obtained by irradiating light of a plurality of wavelengths from a laser apparatus is being researched. For example, Journal of Biomedical Optics 14(5), 054007 focuses on the point that the optical absorption spectrums are different with oxygenated hemoglobin and reduced hemoglobin existing in the blood, and describes the method of calculating the oxygen saturation in the blood by using a plurality of wavelengths.
Japanese Patent Application Laid-Open No. 2012-173246 discloses a photoacoustic apparatus in which a shutter that opens/closes to control the passing of a laser beam is provided on a light path of the laser beam between a laser light source and a biological tissue. With this apparatus, a laser beam can be stably irradiated by performing the control of closing the shutter until the laser beam is stabilized and opening the shutter at the timing of irradiating the laser beam.    Patent Literature 1: Japanese Patent Application Laid-Open No. 2010-022812    Patent Literature 2: Japanese Patent Application Laid-Open No. 2012-173246    Non-Patent Literature 1: Journal of Biomedical Optics 14(5), 054007